One of the core functions of government is to defend the nation from all enemies, foreign and domestic — that’s part of the oath of enlistment that all service personnel take. But only a flinty, clear-eyed — and politically incorrect — assessment of all threats can enable the military can do its job.

Today, however, the brass at the Pentagon seems hell-bent on turning the world’s most powerful military into an arm of the PC Police, a fresh field for “politically correct” bureaucrats on which to push their morally blind relativism.

Take the recent Defense Department briefing document that classified Catholics and Evangelical Protestants as “extremists” — the moral equivalent of al Qaeda and the Ku Klux Klan. It also lumped Christians together with free-floating “Islamophobia,” Hamas, Sunni Muslims, the Jewish Defense League and the backwoods Hutaree militia as potential threats to the Republic.

“Religious extremism is not limited to any single religion, ethnic group, or region of the world,” the briefing paper notes, which is true: The military must prepare for every eventuality, however remote, which is why we have plans for war with Canada and France, should the need arise.

But including half the country’s population on a list of potential terrorists does seem a bit extreme — especially when some 40 percent of active-duty military self-identify as evangelicals.

The Army quickly disavowed the presentation and blamed it on faulty “Internet research” by an Army Reserve figure outside the chain of command.

Phi Beta Iota: The Reservist, whose briefing we have not seen, has undoubtedly been misrepresented. It is not entire religions that are a threat, but rather small pockets of traitors within those religions — Opus Dei, Pentecostalists, and Zionist Jews are all legitimate religious movements, and also home to selected traitors. This is discussion is more properly a very secret one, to be pursued by an utterly ruthless counterintelligence service capable of culling the herd with efficiency. Traitors are motivated by religion, ideology, and money — as a general statement. Absent leadership with integrity, this discussion is also irrelevant.